Speed regulating devices for use on railroad cars



y 1959 P. J. NEFF ET AL 2,886,144

SPEED REGULATING DEVICES FOR USE ON RAILROAD CARS Filed May 10, 1955 I 2 Shets-Sheet 1 INVENTOR. PAUL J .IVEF'F I BY uwemc: k. CHRIST) H4212 rd M425 6 DAN/EL Mc/Nrr'ms May 12, 1959 P. J. NEFF ETAL 2,886,144

SPEED. REGULATING nsvzcss FOR us}: on RAILROAD CARS Filed May 10, 1955 2 Sheets-Sheet 2 FIG. 2.

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l l I I L J LMJ M 2/0 //VVA/7'0/?$ PAUL J. NEFF LAWRENCE R. CHRISTY HARRY S. MARSH DANIEL MCINTYRE {United States P t SPEED REGULATING DEVICES non USE 0N RAILROAD CARS Paul JrNetf, St. Louis, Lawrence R Christy, University City, Harry S. Marsh, PasadenaPark, and Daniel McIntyre, Atfton, Mo.; Margaret Philbrook Netf and Mercantile Trust Company, executors of said Paul J. Nelf, deceased, assignors to said Lawrence R. Christy, as trustee Application May 10, 1955, Serial No. 507,222

6 Claims. or. 188-153) This invention relates to improvements in railroad cars.

device which utilizes a spring biased latching means to i maintain the existing brakes of the car in light engager ment with the wheels of the car during switching and like operations, and utilizes the air pressure of the airbrake system of the car to overcome the spring and remove the latching means so the brakes can become completely disengaged from the wheels when the car is integrated into a train. The device functions as an accessory to the conventionalbraking equipment found on railroad cars and thus requires a minimum of additional parts and entails a rninimmn of labor to install.

of the air b rake rigging with which it coacts. However, when the brake shoes or other parts of the air brake rigging wear, that movable element can respond to emergency braking to engage and move the speed-restricting device. That movement will advance the speed-restricting device toward wear-compensating position; and the detent will permit that movement to. take place and will thereafter hold that device in wear-compensating position. This is desirable since it provides automatic movement of the speed-restricting device to wear-compensatingposb tion. It is therefore an object of the present invention to provide a speed-restricting device that can,.under conditions of emergency braking and wear of the brake shoes or other parts of the brake rigging, be struck and moved to wear-compensating position by the movable element of the brake rigging.

Other and further objects and advantages of the present invention should become apparent from an examination of the drawing and accompanying description. Inthe drawing and accompanying description a preferred embodiment of the present invention is shown and described but it is to be understood that the drawing and accompanying description are for the purpose of illustration only and do not limit the invention and that the invention will be defined by the appended claims.

Inthe drawing, Fig. 1 is a generally schematic, partially sectioned, view showing the air brake valve housing, the air brake cylinder, the brake pipe, and other elements of a typical air brake system associated with the speedrestricting device that is disclosed by said co-pending application and that can be mounted in accordance with the principles and teachings of the present invention,

The speed-restricting device disclosed by the said copending application should be capable of performing its speed-restricting functions irrespective of the wearing of the brake shoes on the railroad car and irrespective of the wearing of other parts of the air brake rigging. The present invention makes this possible by providing a mounting, for the speed-restricting device of the said co -pending application, which enables that speed restricing device to be moved to compensate for such wearing of brake shoes or other parts. Such a mounting avoids any need of a precise positioning of the speed-regulating deviceof the said co-pending application, and it also avoids any need of frequent adjustments in the position of that speed-regulating device. It is therefore an object of the present invention to provide a mounting, for the speeddestricting device of a railroad car, that enables that device to be moved tocompensate for wearing of-the hrake shoes or other parts of-the brake rigging. :The mounting provided by the present invention is equipped with a detent that readily permits the speedrestricting device to be moved toward compensating position and that willthereafter hold that device in compensitting position. Further, that detent permitsthat device tobe moved successively to a number of. compensating positions. Such a detent is desirable since it.enahles i the position of the speed-restricting device to be profgres sively advanced, and it enables that device to maintain itself in any of those positions. It is therefore an object of the present invention to provide a mounting, for'the speed-restricting device of a railroad car, that has a detent which can readily permit that device to be advanced successively to a number. of compensating positions and that can maintain that device in those positions. 1

- The; speed-restricting device. withzwhich the. present inventionris usableis disposed adjacentybut isjnormally out of, the path of movement of the movable element Fig. 2 is a side elevational view of the speed-restricting device of Fig. 1 and the mounting device therefor,

Fig. 3 is a larger scale, sectional view of the mounting device of Fig. 2, and it is taken along the plane indicated by the line 3-3 of Fig. 2, and i Fig. 4 is another sectional view of the mounting device of Fig. 2, and it is taken along the plane indicatedbyi the line 4-4 of Fig. 2.

Referring to the drawing in detail, the numeral 108 denotes a cylinder which has a radially extending annular flange 110 adjacent the open end thereof. A cylinder extension 112 has a radially extending annular flange 114 that is registerable with the flange 110 on the cylinder 108. A packing ring or washer 116 is disposed between and seals the flanges 110 and 114 of the cylinder 108 and the cylinder extension 112. An O-ring 118 is disposed in a groove in the left hand end wall of the cylinder extension 112 and a felt swab 122 is disposed in an annular groove 120 at the right hand end of the cylinder extension 112. A vent 124 is provided in the cylinder extension 112. i i

A piston 126 extends through the cylinder extension 112 and into the cylinder 108. This piston has a metal washer 128 on the end thereof and has a second metal washer 132 which coacts withthe Washer 128 to clamp a flexible cup washer therebetween. A nut 134 is threaded onto the end of the piston 126 to maintain the washers 128, 130 and 132 in intimate engagement. The metal washer 128 bears against and is guided by the inner surface of the cylinder 108, and the flexible cup washer 130 bears against the inner surface of the cylinder 108 and forms a substantially air tight seal therebetween. The metal washer 128 can bear against the O-ring 118 when the piston is in its right hand position and will coact with that O-ring 118 to provide a seal between the piston and the cylinder extension 112. The packing ring or washer 116 will provide an air tight seal between the cylinder 108 and the cylinder extension 112. A preloaded helical spring 136 is disposedewithin the cylinder extension 112 and it bears against the washer 128 and against the p0rtions of cylinder extension 112 which define the groove 120. This spring'will normally bias the piston to the left, as viewed in Fig. l, but will be overcome by the forces exerted on the piston and its associated washers by compressed air in the cylinder 108. The right 'hand end of the piston 126 has engaging meanspreferably-in the form of a ho'ok'142 thereon and that hook is heldin position by a nut 144 on the end of'thepiston 126. This hook extends down below and will underlie the extension 146 of a live cylinder lever whenever that live cylinder lever is in fully releasedposition. A projection 148 is "formed on the outer end of the extension 146 to prevent accidental separation of the live lever and the hook 142, when that 'lever'and hook are in engagement with each other. The spring 136 will normally be held in compressed position, as shown in Fig. l, by air conducted to the cylinder 108 bythe conduit 138 which has a flow restrictor 140 intermediate the ends thereof. However, when thepressure in the cylinder 108 isexhausted back'through the conduit 138 and the flow restrictor 140 to the trainline, not shown, and vents to the atmosphere, the spring 136 will force the piston 126 to the left. At such time the hook 142 will engage and-restrain the extensiorr'146.

The cylinder 108, the cylinder extension 112, the piston 126, the extension 146 of the'live cylinder lever and the parts associated with them are identical in structure, function and operation to the identically-numbered elements in the said co-pending application. Moreover, the device in Figs. land 2 hereof is generally illustrative 'of all of the speed-regulating devices of said co-pending application; and the mounting for the device of Figs. 1 and 2 hereof is generally illustrative of mountings that could be used for the other embodiments disclosed by *said-co-pending'application.

As indicated in Fig. 2, the cylinder 108 can be provided with a radially extending plate-like securing element 200. For convenience, that element can be cast as an integral part of that cylinder. However, if desired, the plate-like element 200 can be made separately and then welded or otherwise secured to the cylinder 108. A generally similar plate-like securing element 202 is provided on the cylinder extension 112. Here again, the plate-like securing element 202 could be cast as an integral part of the cylinder extension 112. However, if desired, that plate-like element could be made separately and then welded or otherwise suitably secured to the cylinder extension 112. A plate-like striking element 203 is also provided on the cylinder extension 112. If desired, this striking element could be integrally formed on thatextension or it could be made separately and then secured to the-extension 112 as by welding or the like. This striking plate will be in register with the live cylinder lever extension 146.

The numeral 204 denotes an end plate "which is adjacent the plate-like securing element 200,-'and the numeral 206 denotes an end plate which is adjacent the plate-like securing element 202. The end plates 204 and 206 are held in rigidly spaced relation by longitudinal "elements 208-and 209. In the preferred form of the present invention, the longitudinal elements 208 and 209 are'angles, and the ends of those elements are welded to the end plates 204 and 206. The welding-of those elements and plates provides a rigid and sturdy frame which has an elongated slot down the longitudinal center thereof. The plate like securing elements 200 and 202 are secured to the end plates 204 and 206 by nut and bolt combinations '210. When those nut and bolt combinations are suitably tightened, the cylinder 108 and'the cylinder extension 112 are 4 but it is shorter than the distance between the vertical legs of the longitudinal'elements 208 and 209. The numeral 214 denotes a closely similar guide plate. The T-shaped guide plates 212 and 214 are mounted in inverted position, and the stems thereof bear against the under sides of brackets 216 and 218. These brackets have horizontally directed central :portions and have vertically directed portions adjacent the ends thereof. The ends of these brackets can be suitably secured to the center sill and side sill of the railroad car. The brackets 2-16 and 218 are of substantial strength, and they will hold the guide plates 212 and 214 fixedly in position throughthe medium of bolt and nut combinations 220. Hence, the T-shaped guide plates 212 and 214 provide fixed points of reference for the speed-restricting device of the present invention.

The bottom surfaces of the brackets 216 and 218 will confine the frame, consisting of theend plates 204 and 206 and the longitudinal elements 208 and 209, against undue upward movement. The cross portions or the T-shaped guide plates 212 and 214 will restrictthat frame against undue downward movement. Hence, the ,"guide plates 212 and 214 will coact with the brackets 216 and 218 to confine the frame, consisting of the endplates 204 and 206 and the longitudinal elements 208 and 209, against undue vertical movement. Furthermore, stems of the guide plates 212 and 214 will coact with the-slot in that frame to confine and guide that frame for recipr'ocal movement.

That reciprocal movement will be in the same direction in which the live lever extension 146 is moved. I I p A U-shaped guide 222 is mounted on the bracket 1218 by nut and bolt combinations 224. The nut and bo lt combinations 224 extend through the closed end of the U; and the U is inverted, as shown particularly in Fig. 4. An opening in one of the arms of the U accommodates a de tent 226 which preferably has two teeth on its inner end. The outer end of the detent 226 is pinned to a handle 228, and that handle extends through an opening in the other arm of the bracket 222. The inner end of the handle 228 is encircled by a helical compression spring 230. One end of that spring bears against the outer arm of the bracket 222, while the inner end of that spring bears against the outer end ofthe detent 226.

The spring 230 biases the detent 226 toward an elongated rack 232 which is mounted on the longitudinal element 209. The rack and detent will beheld in register with each other so that the spring will normally be able to move the detent 226 into engagement with the teeth on the rack 232. Whenever the detent 226 does engage teeth on the rack 232, the detent will prevent movement of the rack 232 to the right, as that rack is viewed in Figs. 2 and 3. However, the spring 230 will yield, when a suitable pull is applied to the handle 228, to permit the rigidly secured to the frame which includes the end plates detent 226 to be moved out of engagement with the rack 232.

A lug 234 is provided on the longitudinal element 209", and that lug has an opening through it. One end of 'a '1 helical'tension spring 236 is inserted in the opening in the lug 234, and the other end of that tension spring is inserted through an opening in the U-shaped guide 222. The spring 236 tends to move the frame, consisting of the end plates 204 and 206 and the longitudinal elements 208 and 209, to the right as that frame is viewed in Figs. 2 and 3. However, the detent 226 normally engages teeth on the rack 232 and prevents such movement. When such movement is desired, the handle 228 can be pulled outwardly to free the detent 226 from the rack 232, and thereupon the spring 236 will move the said frame to the right. Such movement will move the cylinder 108-and the cylinder extension 112. to'the right.

Such movement of the cylinder 108 and the cylinder extension 112 is permitted because of the flexible conduit 238. That conduit will readily bend to permit assent;

ieciprocation of the cylinder 108 and the cylinder extension 112 relative to the train line 104. t t

In mounting the cylinder 108 and the cylinder extension 112 on the car, the frame which includes the. end plates 204 and 206 and the longitudinal elements 208 and 209 is firstassembled with the cylinder 108 and the cylinder extension 112 by the bolt and nut combinations 210. Thereafter, the frame is propped up in position adjacent the brackets 216 and 218, and thereupon the guide plates 212 and 214 are bolted to those brackets by means of the nut and bolt combinations 222. As the cylinder 108 and the cylinder extension 112 are moved up into proximity to the brackets 216 and .218, the hook 142 should be placed in proximity to the live cylinder extension 146, as indicated in Fig. 2. Thereupon the handle 228 should be pulled outwardly to compress the spring 230 andtomove the detent 226 out of engagement with the teeth on the rack 232. As this is done, the spring 236.

system, and thus the mounting assures and complete;

. as well as automatic, compensation for wear.

will tend to pull the frame and the cylinder and cylinder 6 extension tothe right as they are viewed in Figs. 2 and 3.. However, suitable forces will be applied to that frame by the installer to set the hook 142 closely adjacent the live cylinder extension 146. Once this has been done, the pull on the handle 228 can be released, and thereupon the detent 226 will engage teeth on the rack 232 andwill hold the frame in the desired position.

While the. frame and the cylinder and cylinder extension are in this position, the. live cylinder lever 146 can operate freely without striking the striking member 203 or the hook 142. Only if the car is cut out ofa train and the air is bled from the air brake system of the car will the hook 142 engage the live lever extension 146,

audit will then do so to keep that lever extension from falling away to fully released position. Hence, the mountings provided for the cylinder 108 and the cylinder extension 112 permit the air brake system to operate without interference.

In the event the brake shoes or some other part of the air brake rigging wears appreciably, the live lever extension 146 will shift to the left; and that extension could actually respond to emergency braking to strike thestriking member 203. If the amount of wear were sufiicient, theengagement between the live cylinder extension 146 and the striking member 203 could cause the cylinder 108 and the cylinder extension 112 to move far enough to the left to move a fresh tooth into engagement with the detent 226. The spring 230 will yield sufiiciently to permit such engagement of that detent and that tooth. Once that new tooth has been engaged by the detent 226, the frame will be held against returning movement to the right. In moving to the left one tooth, the cylinder 108 and the cylinder extension 112 moved the hook 142 to the left and therefore compensated for the shift of the live lever extension 146 to the left due to wear. Hence, the mounting for the cylinder 108 and the cylinder extension 112 automatically compensated for wear and placed that cylinder and cylinder extension in position where it would not interfere with service braking operations. Furthermore, it kept the forces exerted by the spring 136, inside cylinder extension 112, uniform by keeping the path of movement of the plunger 126 uniform despite the shift in the position of the live lever extension 146.

In the event additional wear of the brake shoes or engage the striking member 203 and move therack 232 to i I the left, as that rack is viewed in Figs. 2 and 3. The

detent would once again permit this movement and then hold the rack and frame against a return to their former of the detent 226 which could be due to wear of the position. The rack. 232 will accommodate all positions,

i If, at some later time, the air brake rigging istightened up, the speed-restricting device can easily be set in position to permit unimpeded operation of that rigging under service braking conditions. All that need be done is to pull the handle 228 outwardly, let the spring move the rack 232 and the frame to the right until. the hook 142 is just free of thelive cylinder lever extension 146, and then release the handle 228. Thereupon the detent 226 will engage the rack 232 and hold it in position. Referring to Fig. l, the numeral 300 denotes the housing of an air brake valve of standard and usual construction; and that housing is connected to the brake pipe 104 of Fig. 2 by a pipe 302. A pipe 318 extends between the housing 300 and the air brake cylinder 20. The piston within, the cylinder 20 operates the push rod 24; and that push rod is connected to the live brake cylinder lever 146 by a pivot 27. a

In the normal position of the various elements of the air brake system, the push rod 24 is retracted withinlthe air brake cylinder 20, and the brake shoes, not shown, respond to their own weight plus the weight of the brake linkage to remain out of engagement with the car Wheels, not. shown. The auxiliary and emergency reservoirs, not shown, of the air brake system are filled with compressed air from the brake pipe, 104, but the valves in the housing 300 keep that airfrom passing to the air brake cylinder 20. When the brakes are to be applied under service conditions, the air pressure in the brake pipe 104 is reduced and the valves in the housing 300 direct air from theauxiliary reservoir to the. cylinder 20. Thereupon, the push rod 24 will move to the left inFig. 1 and will enable the lever146 to cause the brake shoes to be applied against the wheels. When the brakes are to be applied under emergency conditions, the air from both the auxiliary and emergency reservoirs is supplied to the cylinder 20, and a stronger force will be applied to the' i 1. In a railroad .car that is equipped with roller bearings and that has a train line and air brakes and an air brake rigging with a movable element, the improvement which includes a speed-retarding device that can selectively permit unrestricted free rolling of said railroad car or can permit restricted rolling ofsaid railroadcar and that comprises a cylinder, a piston that is disposed within and is movable relative to said cylinder, a flexible conduit extending between said cylinder and said train line, a spring biasing said piston for movement relative to said cylinder, a latch connected with said piston, said latch being registerable with said movable element of the air brake rigging of said railroad car and being movable to latch said movable element of said air brake rigging against movement to fully released position and thereby apply a speed-restricting force to the wheels: ofsaid railroad car, "a mounting for said cylinder that holds and guides said cylinder for reciprocation relative to said railroad car, said mounting holding and guiding said cylinder for reciprocation approximately parallel to that of said movable element of said brake rigging, a movable detent that is movably mounted adjacent said mountingand is biased into position to resist movement of said cylinder in one direction, a surface that is connected with said cylinder and is in register with but is normally disposed beyond the path. of said movable element of said brake rigging, said surface being adapted to be engaged by and to be moved in a direction opposite to thefirst said direction .by ,saidmovable element ofsaid brake rigging whenever wear ots'aid brake rigging enables said movable element during emergency braking to shift'it's path of move-' ment, said detent movin against the bias thereon to pen mitsaid cylinder to move in saidopposite direction but thereafter moving in response to the bias thereon to hold said cylinder against movement in the first said direction, said spring biasing said piston and said latch to speedrestricting position but said piston responding to air con-. ducted to said cylinder from said train line by said conduit during'service conditions to overcome the bias of said spring and thereby permit unrestricted free rolling of said railroad car, said spring acting whenever the air brakes have moved'to full braking position and whenever the air 'brake system and said train line of said railroad car are devoid of Compressed air to move said piston and said latch to a positionadjacent said movable element of said air brake rigging, whereby said latch can keep said brake rigging from falling to fully released position.

2. In a railroad car that is equipped with roller bearings and that has a train line and air brakes and an air brake rigging with a movable. element, the improvement which includes aspeed-retarding device thatcan selectively permit'unrestricted free rolling of said railroad car or can permit restricted rolling of saidlrailroad car and that comprises a cylinder, a piston that is disposed within and is movable relative to said cylinder, a flexible conduit extending between, said cylinder and the train line of said railroad car, a latch connected with said piston, said latch being registerable with said movable element of the air brake rigging of said railroad car and being movable when said piston moves to latch said movable'element of said air brakerigging against movement to fully released position and thereby apply a speed-restricted forceto the wheels of said railroad car, amounting for said cylinder that holds and guidessaid' cylinder for reciprocation relative to said railroad car, said mounting holding and guiding said-cylinder for reciprocation approximately parallel to that of said movable element of'said brake rigging, a detent and a rack,- said rack being connected with said cylinder, said detent and rack normally holding said cylinder in a normal position, asurface that is connected with said-cylinder and is inregisterwith but is normallybeyond the path of said movable element, said surface being adapted to be moved-by said movable element of said rigging against movement to fully released position and thereby apply a speed-restricting'force tq thewheels-of said railroad car, a mounting for said cylinderthatlioid-s and guides said cylinder forreiproeatidnrlativ=to said railroad car, said mounting holdin and' guiding seid cylinder for reciprocation in the same direiction that said movable element of said brake riggingmoves; a detent, a rack that isvconnected with said cylinder, asurface' that is connected with said cylinder and is inregister'withbut is normally beyond the path of said movable element of said brake rigging, said surface beingadapted to be en gaged by and to be moved by-said movable element of said brake rigigng whenever wear of said brake rigging enables said movable element during emergency braking to shitt its path of movement, a second spring biasing said cylinder against such movement, said detent moving away from said rack and said secondspring;yielding-to permit said cylinder to be moved bysaid'member of said air brake rigging, said detent thereaftermoving into engagementwith said rack to hold said cylinder against accidental return to its iormerpositi'on, the first said spring biasing said piston and said latch to speed-restricting position but said pistonresponding to airconducted-to said cylinder from said train lineby said-conduit during serviceconditions to-overcomethe bias of saidfirst spring and thereby permit unrestricted free rollingof saidrail brake rigging-wheneverwear of said brake rigging enables said movable element during-emergency braking -to' shift its path of movement, said detent moving away from said rack to permit said cylinder to be moved by said member of said air brake rigging but thereafter moving into engagement with said rack to hold said cylinder against accidental return to its former position, said piston and said latch being biased to speed-restricting position but responding to air conducted tosa-id cylinder from said train lineby said conduit duringservice conditions to -pertm'it unrestricted' free rolling of said railroad car, said latch acting whenever the air brakes have moved to full braking position and whenever the air brake system and said train line of said railroad car are devoidof compressed air to keep sa'id brake rigging from falling to fully released position.

3. In a railroad car that is'equipped withroller bearings and that has a train line and air brakes and an air brake rigging with a movable element, the improvement which includes a speed-retarding-device that can selectively persaid latch bein registerable with said movable element 'mit unrestricted free rolling of said railroad car or-can 'permitrestricted rolling of said railroad car and that comprises a cylinder, a piston that is disposed within and is movable relative to said cylinder, a flexible conduit' extending-between saidcylinder and the train line of said railroad car, a spring biasing said piston for movement -relative to said cylinder, a latch connectedwithsaid piston,

P h rec p oca ion an a et n fil e road car, said first spring acting whenever-the air-brakes have moved to fully braking position-and whenever the air brake'systemand said train line of said'railroad' calr are devoid of compressed air to 'movesaid pistonand said latch to a position adjacent said movable element of said air brake rigging whereby saidlatch cankeep-said brake riggingfrom fallingto fully released position I v .4; Ina'railroad carhthat is equipped with roller-bearings and that has a train line and air brakesand an .air brake vrigging with an element that moves -.to. one end of a path of reciprocation when said brakes are applied and moves to the opposite end of said path of reciprocation when said brakes are released, the improvement iwhich includes a speed-retarding .device thatcan .selectivelyi'pefr: mit unrestricted free rolling of said railroadrear torcan permit restricted rolling of said railroad .caryand tthfit comprises a cylinder, a pistonthat is. ,disposedavithin and ismovable relative to said cylinder, 1a l'flerr ible con,- duit extending between said cylinder and said train line, a latch that isconnected with said pistonyanradjustable mounting for said cylinder, a surface that is conncctedrwith said cylir'ider and is in ;register with said reciprocagble ,Glfi: m n said mounting holding ai s rf ce adiaqen bm b y nd said :one ,end f ai P th of re ip oca ion, said P on respondin to ir p s re in sa i ai 'lin to h l sai la ch adja :bu bey n i oppo it end iQ :s Path of rec procatioms i air br k r sponding to re u ti n in h .pr ureli -sai t a naliue t move a rec p c l l en to s id o end of sai -oath of a ip catio id p s act n W en v Said train lin 515 dev i o a t mo esaid lat is d o en a sai Pa f t q p e pnv o, pla e sa s pq n said b ak i g re po d n to ear n of Said ake i nd't emer en ib a i gt o shi t a r tpath c reqi rqsat q tc ard sai u g and cause aid rec ps h e e em n t en a e a d a av s s sur snd he ebv-sh a out ace e nd tt esnd fa -permit said cylinder and surface ,to sh'ft and tha t after I-holds said cylinder and surface againstlretiir iiing mo ment. I t In ara t ad a ha i eq ip edlwit ro len ssrr s and t a ha a, t a n line and ,a br ke and I a i "brake rigging with a live cylinder ,leyer that m was to one 0 end "of a path of reciprocation When said air are applied and moves to the opposite end of said path of reciprocation when said air brakes are released, the

, improvement which includes a speed-retarding device that cation, a spring biasing said latch toward said one end;

of said path ofreciprocation, said piston responding to air pressure in said train line to hold said latch adjacent but beyond said opposite end of said path of reciprocation, said air brakes responding to reductions in the air pressure in said train line to move said live cylinder lever to said one end of said path of reciprocation, said piston acting whenever said train line is devoid of air to move said latch toward said one end of said path of reciprocation to place said latch in position to hold said live cylinder lever adjacent but short of said one end of said path of reciprocation and thereby keep said brake rigging from falling to fully release position, said brake rigging responding to wearing of said brakes and to emergency braking to shift said path of reciprocation toward said surface and cause said live cylinder lever to engage said surface and thereby shift said surface beyond the end of said shifted path of reciprocation, and a detent that is movable to permit said cylinder and surface to shift and that thereafter holds said cylinder and surface against returning movement, said detent normally being engageable with a toothed rack connected to said cylinder, said flexible conduit permitting said shifting of said cylinder.

6. In a railroad car that is equipped with roller bearings and that has a train line and air brakes and an air brake riggin with an element that moves to one end of a path of reciprocation when said air brakes are applied and moves to the opposite end of said path of reciprocationwhen said air brakes are released, the improvement which includes a speed-retarding device that can 10 selectively permit unrestricted free rolling of said railroad car or can permit restricted rolling of said. railroad car and that comprises a cylinder, a piston that is disposed Within and is movable relative to said cylinder, a flexible conduit extending between said cylinder and said train line, a latch that is connected with said piston, said latch having a path of reciprocation that is partially coextensive with the path of reciprocation of said element but that extends beyond said opposite end of the path of reciprocation of said element, an adjustable mounting for said cylinder, a surface that is connected with said cylinder and is in register with said reciprocable element, said mounting holdin said surface adjacent but beyond said one end of said path of reciprocation, said piston responding to air pressure in said train line to hold said latch adjacent but beyond said opposite end of said path of reciprocation, said air brakes responding to reductions in the air pressure in said train line to move said element to said one end of said path of reciprocation, said piston acting whenever said train line is devoid of air to move said latch toward said one end of said path of reciprocation to place said latch in position to hold said element adjacent but short of said one end of said path of reciprocation and thereby keep said brake rigging from falling to fully released position, said brake rigging responding to wearing of said brakes and to emergency braking to shift said path of reciprocation toward said surface and enable said reciprocable element to engage and move said surface and thereby shift said surface beyond. the shifted path of reciprocation of said reciprocable element and cause the reciprocable path of said latch to shift toward said one end of the path of reciprocation of said element whereby said paths of reciprocation can maintain their normal, partially coextensive relationship, said flexible conduit permitting said shifting of said cylinder.

References Cited the file of this patent UNITED STATES PATENTS 1,907,174 Blair May 2, 1933 2,211,890 Farmer Aug. 20, 1940 2,531,055 Kirk Nov. 21, 1950 

